Who do I make a complaint about customer service for Chill insurance?

As the title says, I want to make a complaint about one of their callers in the customer service I dealt with today. He wasn't just rude, he was aggressive and completely out of line after I rang to ask why their was incorrect information on my insurance documents that were sent through email.

Thankfully I was passed on to another person who was really polite and helpful and was able to sort it out in a few minutes and send new documents. But this first guy was so awful he nearly had me in tears.

I don't know why he was so rude, and aggressive and not to mention he cut me off before I could ask how it was to be sorted. I honestly don't know why he was like that because if the whole conversation was listened back to, I could barely get a word in. I can only think the only thing that made him go like that was because I said it was important and needed to be sorted before I could drive the car, and had been trying to get through to his number but kept being put on voicemail. But I don't think that could be enough to make someone go off the way he did.

I know all those calls are recorded so I hope someone listens back to them and knows what he was like speaking to me today. I don't even know who to speak to this about because no one should put up with someone like him on the phone when the fault was them messing up information. It's really frustrating and upsetting. I had sorted the insurance out yesterday, because a car is really important to get my parents to and from hospital and doctor appointments, collecting their food and essentials as they can't leave the house, beside my mum being disabled, so it's a life saver for them.

I find it really hard to deal with people who are like that, I'm a super anxious person, and those kinds of things really knock me back when they can seem so small to others so yeah, just wanted to know who I can send a complaint to, in email or something. Can't seem to find the right contact information online.

Thank you.